Oh, hey, high-fives to fellow practicing LDS! (I had no idea you were LDS! I’ve been only sporadically on the board lately, so am kind of out of touch. Briefly, I’m a devout Mormon in terms of practice, but have a complicated relationship with faith.)
I absolutely, absolutely agree with you that you can be forgiven for whatever you do. WHATEVER you do. That is a basic tenet and I will defend you from anyone giving you crap about it. 
But, as Mormons are fond of saying, there are consequences that can’t be gotten out of. Here, you did engage in an emotional affair. (I’m totally surprised that no one has said that in those words yet – unless I missed it?) You directed at another man the romance and erotic thoughts and attraction that you promised to your husband when you got married.
And look, I get that you got carried away. Obviously I would be the last person to judge you for that, given my story. But there are now consequences. It sucks to let go of that emotional high. It sucks that your platonic friendship is never going to be the same again. And you will have to live with that. And repenting is hard, as you’re finding out! And you have to live with that too. I’ve been through it, as I’ve said, and I know it sucks a LOT.
The consequences aren’t as bad as if it had gotten physical. Then you’d have much worse marital, religious, and emotional consequences. (Not even to mention the possibility of disfellowship/excommunication and divorce – purely on the emotional level, if you feel as bad as you do now, can you imagine how badly you’d feel if it had gotten physical and then you had to break it off?)
If you are a devout Mormon, you know that Heavenly Father will get you through this. He knows it sucks. He knows you feel like crap. He’ll help you. He wants to help you get through this without destroying more of your life in the process.
I’ll pray for you too if you would like me to.
(And, somewhat off-topic but I think it might be relevant – Mormonism historically has kind of sucked with practical advice for marriage. Do you think you communicate well with your husband? (Hint: I suspect the answer is no.) Can you work on improving that? Can you tell him you guys need to take more time to be just the two of you? Date nights every Friday, as Mormons are supposed to do?
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